D_1(~2B_2g)- D_O(~2Au) fluorescence from the matrix-isolated perylene cation following laser excitatin into the D_5(~2B_3g) and D_2(~2B_3g) electronic states

摘要

Fluoresence spectra of the perylene cation, isolated in an aragon matrix and pumped by direct laser excitation via the D_2(~2B_3g) <- D_O(`2A_U) and D_5(~2B_3g) <- D_O~(2A_u) transitions, are presented. Direct excitation into the D_5 or D_2 states is followed by rapid nonradiative relaxation to D_1 that, in turn, relaxes radiatively. Excitation spectroscopy acaross the D_2(~2B_3g) <- D_O(~2A_u) transition near 730 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by a comparison of spectral intervals with calculated normal mode frequencies, with the strongest IR bands leading to the most intense vibronic bands.